Corrosion Behavior of Epoxy Resin Filled with Ground Resin in Sulfuric Acid Solution

Abstract

An epoxy resin cured with acid anhydride has good resistance to acid solution and an epoxy resin cured with amine has poor resistance. Two types of ground fillers were made from these two types of epoxy resins. Four kinds of recycled materials composed of two types of fillers and two types of matrix resins were prepared. The corrosion behaviors of the four kinds of particle filled epoxy resins (and other two types of neat resins) in sulfuric acid solution were investigated. In case the matrix was an epoxy resin cured with acid anhydride, flexural strength after immersion test in sulfuric acid solution normalized by that in pure water did not decrease for the neat epoxy resin and the recycled material filled with particles of epoxy resin cured with acid anhydride. With respect to the recycled material filled with particles of epoxy resin cured with amine, the normalized flexural strength decreased by degradation of exposed filler on the surface of specimen. On the other hand, in case the matrix was an epoxy resin cured with amine, the weight and thickness noticeably increased by immersing in sulfuric acid solution for the neat epoxy resin, the recycled material filled with particles of epoxy resin cured with acid anhydride and the recycled material filled with particles of epoxy resin cured with amine. For the three kinds of materials, the retention of flexural strength of dried specimens increased immediately after immersion tests started and then decreased. Sulfuric acid penetrated into all materials as results of X-ray elemental analysis. There was no distinct difference in decrease of strength of three kinds of materials and penetration of sulfuric acid into them.